Prolonged Use of Nimotuzumab in Children with Central Nervous System Tumors: Safety and Feasibility

Primary brain tumors constitute the most frequent solid tumor of childhood. High expression of the epidermal growth factor receptor (EGFR) protein has been associated with tumor progression and enhanced tumorigenicity in adult and children gliomas. Nimotuzumab is a humanized antibody that targets the EGFR and has proven efficacy in adult and children gliomas. To provide a new therapeutic option for patients with active, poor prognosis central nervous system (CNS) tumors and to evaluate the feasibility and safety of long-term nimotuzumab therapy in children with diverse CNS tumors, an expanded access program was launched at the Juan Manuel Marquez hospital. Patients were required to be 18 or younger and have one CNS tumor: low-grade glioma (LGG) or high-grade glioma (HGG), brainstem glioma (BSG), ependymoma or primitive neuroectodermal tumor (PNET), and a Lansky or Karnofsky performance status >= 40. Treatment consisted of weekly nimotuzumab administered at 150mg/m(2) for 12 weeks, continuing every 14 days in the absence of severe condition worsening or unacceptable toxicity. Nimotuzumab was administered alone or in combination with radiotherapy, chemotherapy, or both, depending on the tumor type, stage, and previous treatment. Eighty-eight patients, 39 with BSG, 25 with HGG, 9 with progressive LGG, 9 with anaplastic ependymomas, and 6 with other tumor types, including PNET, neuroblastoma, meduloblastoma, and thalamic tumors, were treated with the antibody. The mean number of nimotuzumab doses was 36, from 1 to 108. The most frequent adverse events were mild to moderate skin rash, mucositis, vomiting, seizures, hypothermia, hyperthermia, and paleness. One patient had a grade 3 mucositis, while the other had a grade 3 bleeding on surgery. Sixteen children stopped treatment after at least 2 years with stable disease, partial or complete response. All children were able to maintain the best response achieved on treatment after a 3-year interruption. In summary, this study shows the feasibility of very prolonged administration of nimotuzumab together with the lack of rebound effect after treatment cessation.